-LRB- CNN -RRB- -- Police expanded their search Friday for a man who either jumped or fell from a small plane as it flew off the Florida coast near Miami .

The pilot of the single-engine Piper PA-46 aircraft called air traffic controllers Thursday afternoon to say his passenger -- the only other person on board the flight -- had fallen out of the plane .

`` He opened the back door and he just fall down the plane , '' the pilot said , according to a recording of the conversation .

The pilot said he was flying at 1,800 feet about two miles from the shore when the man fell . Authorities identified the man as Gerardo Nales , a 42-year-old man from Key Biscayne , Florida .

After searching until dark Thursday , authorities resumed their efforts early Friday , expanding the search area based on currents and weather conditions , police said .

Police think it 's unlikely Nales could have survived the fall . They 're describing the search as a recovery mission .

A police spokeswoman said it was unclear whether Nales accidentally fell out of the plane or deliberately jumped .

Investigators questioned the 47-year-old pilot but did not release his name . Homicide detectives also are involved , as they are in all death investigations , Miami-Dade police spokeswoman Sgt. Robin Pinkard said .

The pilot first told air traffic controllers that a door was open on the plane , then added that a passenger had fallen out .

`` I have a door ajar , '' he said , `` and a passenger that fell down . ''

The Piper PA-46 -- a private plane -- went on to land safely at Kendall-Tamiami Executive Airport , the Federal Aviation Administration said . Baez declined to say whether the owner of the plane was on the flight .

CNN 's Catherine E. Shoichet , Alina Machado , Mike M. Ahlers and Brian Rokus contributed to this report .

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NEW : Police identify man who fell from plane as a 42-year-old from Key Biscayne

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Police expand search for man who fell or jumped from plane

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Pilot : `` He opened the back door and he just fall down the plane ''

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Police think it 's unlikely the man could have survived